Because radiation therapy relies upon the often small margin of differential radiosensitivity between normal and malignant tissue, the radiation dose delivered must be carefully balanced to destroy all malignant cells while sparing the surrounding normal tissue. The present study in rodents is an attempt to widen the differences in sensitivities of salivary glands and their neoplasms by using a radioprotector (WR-2721) in order to spare the normal parotid gland and a radiosensitizer (Ro-07-0582) to more effectively irradicate a salivary gland malignancy. The project will study the protecting and sensitizing properties of both compounds, independently at first and then together, upon normal and malignant tissues in the hope that the two compounds, simultaneously administered, can widen the radiosensitivities and so enhance the therapeutic index and the efficacy of radiation therapy. The study is also probing the possibility of utilizing other, already available drugs which has already shown prelimininary promise and have in common secretion-inducing properties, e.g., isoproterenol, as a possible substitute for the still experimental radioprotector, WR-2721. In addition we will investigate cAMP as a chemoradioprotector and as the induced intracellular compound conferring the production. Finally, should other effective protectors of normal tissue be found we will test their compatibility with the tumor radiosensitizer Ro-07-0582.